Logic Paradoxes
French Paradox - The French eat rich food, butter, cheese, and drink wine - yet have lower heart disease rates than A...
Buttered Cat Paradox - Cats always land on their feet. Buttered toast always lands butter-side down. What happens if you st...
Raven Paradox - To confirm "All ravens are black," seeing a black raven helps. But logically, seeing a green apple (...
Bell's Theorem Paradox - Quantum correlations violate classical probability rules. Measurements on entangled particles show r...
2FA Backup Paradox - Two-factor authentication needs backups for when you lose your device. But secure backups defeat the...
Paradox of Meritocracy - Organizations that explicitly embrace meritocracy often become less fair. Believing the system is fa...
Transparency Paradox - More workplace transparency can backfire. When employees know they're being watched, they hide creat...
Gender-Equality Paradox - Countries with more gender equality have fewer women in STEM. More freedom amplifies rather than eli...
Aggregator Paradox - Platforms that aggregate content to serve users better eventually control that content. The aggregat...
Radioactive Wildlife Paradox - The Chernobyl exclusion zone is now a wildlife paradise. The absence of humans is better for animals...
Sorites Paradox - Remove one grain from a heap and it's still a heap. But repeat enough times and you have no heap. Wh...
Dome Paradox - A ball balanced on a special dome can spontaneously start moving without any external cause, challen...
Bootstrap Paradox - In time travel, information or objects exist without ever being created. Who composed Beethoven's sy...
Bonini's Paradox - As a model becomes more complete and realistic, it becomes harder to understand. A perfect model is ...
Polanyi's Paradox - "We know more than we can tell." Much human knowledge is tacit and cannot be explicitly stated - whi...
Grelling-Nelson Paradox - Is "heterological" (a word that doesn't describe itself) heterological? If yes, then no. If no, then...
Curry's Paradox - "If this sentence is true, then Santa exists." This seemingly absurd conditional can prove anything!...
Berry Paradox - "The smallest integer not definable in under sixty letters" - but that phrase has fewer than sixty l...
Allais Paradox - Human choices in gambles systematically violate expected utility theory. Certainty has disproportion...
Inventor's Paradox - Sometimes it's easier to solve a more general problem than a specific one. The extra generality prov...
Drinker Paradox - "There is someone in the pub such that if they are drinking, everyone is drinking." This bizarre sta...
Catch-22 - A soldier who wants to be declared insane to avoid combat is deemed not insane for that very reason....
Barber Paradox - A barber shaves all and only those men who do not shave themselves. Does he shave himself? If yes, t...
Crocodile Dilemma - A crocodile steals a child and promises to return it if the father correctly guesses what the crocod...
Paradox of the Court - A law student agrees to pay his teacher after winning his first case. The teacher sues - if the stud...
Epimenides Paradox - A Cretan says: "All Cretans are liars." If true, then the Cretan is lying, so it's false. If false, ...
Card Paradox - "The next statement is true. The previous statement is false." Neither sentence is self-referential,...
Pinocchio Paradox - What happens if Pinocchio says "My nose grows now"? If true, his nose shouldn't grow. If false, it s...
Quine's Paradox - "Yields a falsehood when appended to its own quotation" yields a falsehood when appended to its own ...
Opposite Day - "It is opposite day today." If true, then it's NOT opposite day. But if it's NOT opposite day, the s...
Barbershop Paradox - Lewis Carroll's paradox: If one of two simultaneous assumptions leads to a contradiction, the other ...
Lottery Paradox - It's reasonable to believe any single ticket will lose, but unreasonable to believe NO ticket will w...
What the Tortoise Said to Achilles - Carroll's paradox: If a premise needs justification that it leads to a conclusion, we need infinite ...
Knower Paradox - "This sentence is not known." If you know it, it's false (so you don't know it). If you don't know i...
No-No Paradox - Sentence A: "B is not true." Sentence B: "A is not true." Neither directly self-referential, yet tog...
Yablo's Paradox - An infinite sequence where each sentence says "all following sentences are false." No self-reference...
Richard's Paradox - We can define a decimal that differs from every definable decimal - but that definition itself defin...
Preface Paradox - An author believes each statement in their book is correct, yet also believes at least one must be w...
Fitch's Paradox - If all truths are knowable, then all truths are known! The modest claim that truths CAN be known imp...
Goodman's Paradox - Define "grue": green if observed before 2100, blue after. All evidence for "emeralds are green" equa...
Morton's Fork - Contradictory observations lead to the same conclusion...
Intentionally Blank Paradox - 'This page intentionally left blank' contradicts itself by not being blank....
White Horse Paradox - Ancient Chinese paradox: 'A white horse is not a horse'....